<!DOCTYPE html>
<html>
<head>
	<meta charset="UTF-8">
	<title>Document</title>
	<style>
		.sanjx, .inner {
			width: 0;
			height: 0;
			/*border: 20px solid red;*/
			border-width: 50px 0 50px 50px;
			border-style: solid;
			border-color: transparent transparent transparent red;
			position: relative;
		}

		.sanjx .inner {
			border-color: transparent transparent transparent #fff;
			position: absolute;
			/* top: 1px;
			left: -50px; */
			top: -50px;
    		left: -51px;
		}

		/***************************************************/

		.sanjx2 {
			width: 0;
			height: 0;
			/*border: 5px solid red;*/
			border-width: 5px;
			border-style: solid;
			border-color: red transparent transparent transparent;
		}
	</style>
</head>
<body>

	<div class="sanjx">
		<div class="inner"></div>
	</div>

	<hr>

	<div class="sanjx2"></div>
	
</body>
</html>